Suction box for the manufacture of paper and similar products



Much 13, 1934. E. LAMORT 1,950,853

` SUCTION BOX FOR THE MANUFACTURE OF' PAPER AND SIMILAR PRODUCTS Filed May 16, 1933 2 Sheets-Sheet l i il ll ll E. LAMORT March 13, y19,34.

SUCTIN BOX FOR THE MANUFACTURE OF PPER AND SIMILAR PRODUCTS Filed May 16, 1933 2 Sheets-Sheet 2 es 31 as l Patented Mar. 13, 1934 PATENT OFFICE SUCTION BOX FOR THE MANUFAC'VI'UBTE 0F PAPER AND SIMILAR PRODUCTS Ernest Lamort, Vitry-le-Francois, France, assignor to Socit E. & M. Lamort Fils, Vitry-le- Francois, France Application May 16, 1933, Serial No. 671,313 In France May 20, 1932 18 Claims.

This invention relates to a system of suction boxes with rolling active surfaces and .frictionless sealing drawers which boxes are to be used a in the manufacture of paper and similar products.

The arrangements in question have these advantages upon the types previously known and hitherto used that they eiIect a saving of wire cloth and power whilst the quality of the products which are manufactured is improved.

It will be useful to remind here that the various types of suction boxes as have hitherto been used in machines for makingv paper or cardboard, or similar machines are divided into two classes;l namely:

Fixed and 'plain surface boxes, to which a longitudinal alternating movement is sometimes imparted and v 4 v r Rotary active surface boxes acting 'at the same time as coating or wet presses; the latter systemvhas' been proposed in view to reduce, particularly in the case yof paper machinery working -at a high linear speed of the sheet, the considerable wear of the wire cloth due to fric- 25 tion on the suction surfaces of the fixed boxes, whilst reducing at the same time the tensile stress upon raid clothes; however, the said fixed boxes cannot thus be dispensed with and the arrangement affords only a partial `solution. 30, Furthermore, the use of the said boxes with rotary cylindrical surfaces do not save power at all. Indeed, the saidboxes are situated either at the end of the wire cloth or placed under i'elts; they consequently act upon an already formed product, and` at the same time by. means of an active surface which is too much reduced, therefore the said boxes are'to be operated with an excessive amount of suction and require a correspondingly high power to maintain a high 40 degree of vacuum, iinally their construction is very expensive. r

Consequently many attempts havebeen made to produce suction boxes with rolling active surfaces implying lower friction stresses, but all such systems have proved unsuccessful due to lack of air tightness: they were in the main, based upon an inconsistency: obtaining tight drawers, consequently sealing drawers, without developing friction stresses between the rotating parts of the same.

The present invention relates to suction boxes ofthe type in which the side walls are com-- pletely or partly constituted by rotative rollers; the two bases of the box are then constituted by iixedpads called drawers and the object of the invention is to prevent air in-leakage through the space or joint comprised between the rotative rollers and the iixed drawers or like parts. According to the invention, a suction which counteracts the air in-leakage is provided adjacent to the joint. In voneof the embodiments the joint is flanged by a drain in which vacuum is set up.

A more advantageous arrangement consists in forcing a fluid under pressure in a nozzle which constitutes an ejector and entrains the air adjacent to the joint. The drawer may be placed at the end of a tube serving to admit the compressed fluid and the latterescapes by a slit shaped as a nozzle and which extends over the whole periphery' of the drawer. The width of the joint is preferably increased towards the base of the box.

The ejecting action may be used not only to prevent the iii-leakage of air, but also to extract air and if necessary water from the box.

However, separate devices may be provided to force compressed air in the slit and to extract air and water from the box; such devices may be so combined that the uid extracted from the box` will be returned under pressurek to the nozzle.

In a particular arrangement, an overflow is provided, so that `water will accumulate in the base oi the box up to the level corresponding to the crest of the overilow and secure tightness of part of the joint. For the upper part of the joint it is useful to provide a deilector which collects part of the water coming from the pulp and conveys said water to the joint.

A suction pipe may-further be provided over the whole length of the box with pads or drawers sliding on the said pipe. The tightness oithe joint may be increased by providing its surfaces with grooves.

The invention has also for its object a suction box constituted by two rotative rollers supporting the cloth, a fixed plate and two bases;

the tightness between rollers and cloth on the one hand, the fixed" plate and the bases from the other hand is obtained as described above. Finally the fixed plate may be replaced by an endless band passing over two rollers. It is understood that the present invention is not limitedto suction boxes used in paper making, and that it may be applied with wire cloth as well as with other sorts of cloths, felts or like materials. For an understanding of the invention refer Figure 1 a front view showing two suctionI boxes constructed according to the present invention;

Figure 2 a longitudinal sectionl along the line II-II of Figure 1, one of the drawers being shown in section and the other from the exterior; L

Figure 3 a section through a vertical plane of another form of drawer;

Figure 4, a section similar to Figure 3 of a drawer provided with an overilow;

Figure 5' a longitudinal section of a suction box in which the drawers may slide upon a hollow rod;

Figure 6, a front view showing laterally and partially in section a suction box in which the base is constituted by a fixed plate;

Figure 7 is a section along the line VII-VII of Figure 6;

Figure 8 shows diagrammatically a suction `box in which the base is constituted byl an endless band.

In Figure 1 is shown a band of wire cloth 1, coated with paper pulp and which is moved in the directionof the arrow 2.

The said band successively travels upon two suction boxes constructed according to the invention; each of said boxes comprises two rollers 3, 4, provided with a copper coveringand bearing along their upper generating line against the lower face of the bandl; a third roller .5 coated with rubber, bears upon the rollers 3, 4, in order to provide a tight joint; the said roller 5 is rotated by means of a device not shown and causes the rollers 3 and 4 to rotate with a circumferential speed equal to the linear speed of the band 1. Consequently, the rollers 3, 4, roll without slipping on the band 1.

In such conditions, the lateral walls of the suction box are constituted by the rollers 3, 4, 5, and by the band 1; on the other hand, the bases of the box or the bases of the prismatic volume dened by the rollers and by the band are constituted by nomotating pads called drawers the one of which, 6, is shown from the exterior at the right of Figure 2,-whilst the other isshown in section at the left on the same gure.

Each drawer is shaped according to the outline of the space comprised between the rollers 3, 4, 5, and the cloth 1; however, the said drawer exerts no friction upon the latter 'parts which are moveable and is separated from them by a space reaching 1 millimetre. As is well known, vacuum is set up into the suction box in order to liberate the paper pulp from its water; due to said vacuum, the air tends to penetrate in the box through the above mentioned space and the present invention enables to prevent such inleakage of air. l

In order to attain the said result, the drawer comprises a head 'l carried at the end of a hollow rod 8; a shell 9 is secured to the rod 8, leaving a space 10 -between its edges 11 and the edges 12 of said head. 'Ihe space l0 is extended over the whole periphery of the drawer and is shaped as a nozzle. Compressed air is forced in the rczi 8 and escapesthrough the nozzle 10, thus producing an ejectingaction; namely, the compressed air stream tends to entrain towards the exterior the iiuids contained in 13, inside the suction box'. The said action may be controlled in order to substantially balance the atmospheric pressure, thus preventing any in-leakage o! air;

` part, larger .quantities of water are available,

furthermore, as shown in Figure 2, a stream of compressed air, suillciently powerful to cause the entrainment of the air and oi the water-contained in the box may be provided. In the lower thus forming an air tight joint in the space of l millimetre comprised between the head 'l on the one hand, the roller 5 and the lower part of the rollers 3, 4, on the other hand. To the upper part of the head 'I is secured a plate 14 parallel to the cloth l, and which will be called hereafter deiiector. The water dropping from the pulp 15 upon said deector, isfdrawn in the adjacent joint and secures tightness. In the said way, both water and air are extracted from the suction box whilst an airtight joint is provided between xed and moving parts.

Since the amounts of water and air to be discharged through the joint vary vaccording tothe level, the joint may be given a width which is in every part proportional to the output to be discharged at the given place; in other words, the value of the space comprised between the drawer and the other members, will vary according to the level; the said value will preferably 100 be the highest at the lower part and will decrease in getting further from the base.

As is well known, the width of the pulp layer 15 may be varied by the longitudinal displacement of the drawers; the nozzle 10 is placed 105 adjacent to the edge of the pulp layer 15.

In Figure 3 is shown a drawer placed between a roller 16 and a cloth 1'1 in the same way as the drawer located at left hand in Figure 2. This new drawer is however constituted by a 119 plate 18, through which passes a pipe 19 connecting the inside of the box 20 to a vacuum pump, not shown. A small space or joint -is provided lbetween the periphery of the plate 18 and the moving parts, all along the said space a sort .115 of drain 21 is provided which communicates by means of conduits 22 with the vacuum pipe 19. In such a way a vacuum is set up in the drain 21, whose value may be so regulated that no objectionable in-leakage of air will take place in the interior 20 oi' the suction box.

In Figure 4 is shown in enlarged scale another type of drawer, positioned in the same way as the drawer shown in Fig'ure 3. Said drawer is provided with a head 23 comprising a compressed air nozzle 24, which operates in a way similar to the nozzle 10 of Figure 2. However, in the circular space 25 an inlet has been provided for air and water coming from the interior of the box. Furthermore, an overflow 26 130 causes the water to accumulate in the box the latter owing in the space 254 only when reaching a level higher than thelevel of the crest'of the overflow 26.

The suction box shown in Figure 5 is distin- 135 guished by the simultaneous use of conduits intended to convey the compressed air to the joints and of a conduit for the extraction of fluids from the suction box. 'I'he said box comprises, as in the preceding embodiments, a large roller 27 and small rollers not shown, bearing along their upper generating line against the lower i'ace oi the wire cloth. Each drawer is consti# tuted by two plates 28, 29 between which compressed air is forced by means oi.' conduit 30; said air escapes through a slit 31 provided between both plates and at their edges; the slit 31 is shaped as a nozzle and similarly to Figures 2 and 4, sets up an ejecting action against the in- 150 leakageot air through the joint; however, on

the oppositeto the case of'Figures 2 and4, the said eiecting action does not result in the` extraction ci the uid from the box 32 and has solely for its object to resist against atmospheric l pressure. For this reason grooves 33 have been provided in the periphery of the plate 28, which also prevent the in-leakages or air.

The plates 28, 29 of each drawer are set in order to slide upon the same hollow rod,34; the location oi the drawers may thus be adjusted according to the width of the pulp layer 35 coated on the cloth 28. Furthermore, the conduit 34 is connected to a vacuum supply, causing the suction of the waterA and oithe air contained in the interior 32 of the box, through the openings 38 provided in the same.

another form oi suction box may be obtained by substituting a xed table 37 (Figures 6 and Il to the large roller 5 shown in Figures 1 and 2. Insuch caseprovisionistobemadetosecure tightness between said table 37 and the rollers 38, 39; to thisv end, compressed air is forced in a nozzle 40 (Figure 6) acting as the nozzle 10 shown in Figure 2; a similar nozzle is provided at the base of the roller 39. Finally the bases or the box are sealed by drawers formed by two plates 40, 4l (Figure '1).

Since the said drawer and the plate 37 are ilxed in normal operation, tightness is easily secured between the two parts; however in order to take care or the displacements oi the drawer due to variations in size, a sealingtongue has been provided at 42. sliding upon the upper face oi the plate 37 until being brought into contact with plate 4l.

Finaliy, Figure 8 shows a suction box inwhich the lower part is constituted by an endless band 43 passing over two rollers 44, 45; the joint between the rollers 44, 45 and the rollers 46, 4'Iisairtightsothattheband43 actsinthe same way as the large roller 5 o! Figures 1 and 2. It will however be noted that a plurality or suction boxes of the said type may be placed directly one after the other, sothat a roller such as 46acts as a partition between each box. In this way not only the overall dimensions are reduced but also the number of the rollers.

In another embodiment of the invention, a plurality of boxes is placed between rollers 46 and4'lsothattheband43actsasacommon base.

Having now particularly described and ascertained the nature di my invention and in what manner the same is to be performed, I declare that what I claim is:

1. A process tor securing air tizhtness of the joint between the moving and the nxed parts in a suction box provided with rollers or similar device in which a suction is provided adjacent to order to counteract the in-leakages 2.1Aprocessaccordhitoclaimhinwhich y 3 the suction is produced by means lof a nozzle in which a iluid under pressure is forced so 'that the said nozzle acts as an ejector.

3. A process according to claim l, in which the electing ei'iect is used to counteract the in-leakages of air.

4. A process according to claim 1, in which the eiecting eiiect is further used to extract air and water from the suction box.

5. A process according to claim 1, in which the suction of the iluid takes place in the box and the uid is then forced in the nozzle.

6. A suction box provided with rollers in which the joint between moving and iixed parts is ilanged by a drain in which vacuum is set up. '1. A suction box provided with rollers in which is provided a nomle directed counter current to the in-leakages oi air and in which may be' 1 forced a iluid under pressure.

8. A suction box provided with rollers in which the drawer is placed at the end oi the admission pipe for the compressed fluid.

9. A suction box provided with rollers in which a slit shaped as a nozzle extends over the whole periphery of the drawer.

10. A. suction box provided with rollers in which the width oi' the joint increases towards the base of the box.

11. A` suction box provided with rollers in which an overflow is provided so that the water will accumulate at the base of the box up to the level corresponding to the crest of the overilow.

12. A suction box provided with rollers in which the iluid to be extracted from the box is admitted on both faces of the stream leaving the' nozzle.

13. A suction box provided with rollers in which at the upper part oi the joint is provided a' defiector which directs towards the same a wgiven amount of the water dropping in the box.

14. A suction box provided with rollers in which the drawers slide upon a hollow rod which is preferably used for the extraction oi. air and water from the box.

15. A suction box provided with rollers in which grooves are provided on the wall of the join y 16. A suction box provided with rollers in which the side walls of the box are constituted by wire cloth, two rollers bearing against the cloth and a ilxed plate.

17. A suction box provided with rollers according to claim 16, in which the air tightness o! the Joint between the med 'plate and the m11-` 13 ersissecuredbymeansofanozzleiedwith compressed iluid.

18. A suction box provided with rollers accordinirtoclaim 16,inwhichthenxedplateisref placed by an endless band bearing upon rollers.

mm LAMORT. 

